Acute oral toxicity (LD50): 9100 mg/kg in the mouse MSDS

Toxicity from overdose is rare but may result from intentional ingestion of potassium. Iatrogenic overdoses may occur ^L2653.

Local irritation after ingestion causes GI upset. Severe hyperkalemia after large IV or oral overdoses causes muscular dysfunction including weakness, paralysis, cardiac dysrhythmias, and rarely death ^L2653.

Mild to moderate toxicity

Nausea, vomiting, diarrhea, paresthesias, and muscle cramps are common. Rarely, gastrointestinal bleed may occur.

Severe toxicity

In severe toxicity, muscular weakness progressing to paralysis may occur. Cardiac arrhythmia often occur at concentrations greater than 8 mEq/L and death from cardiac arrest at concentrations of 9 to 12 mEq/L or higher. Characteristic ECG findings occur in the following order: peaked T waves, QRS complex blends into the T wave, PR interval prolongation, P wave is lost and ST segments depress, merging S and T waves, and finally, sine waves. The presence of the sine wave is a near terminal event, signaling that hemodynamic collapse and cardiac arrest are near. As serum hyperkalemia is corrected towards normal concentrations, the ECG changes resolve in reverse order ^L2653.